PREPARATION OF (ETA(5)-RC5H4)(2)MO-2(CO)(2)(MU-PHS)(2) (R=H, MECO) BYTHE REACTION OF [ETA(5)-RC5H4MO(CO)(2)](2) WITH (MU-PHS)(2)FE-2(CO)(6) - CRYSTAL-STRUCTURES AND ACETYL TRANSFORMATION REACTIONS OF 2 ISOMERS TRANS ANTI-(ETA(5)-MECOC5H4)(2)MO-2(CO)(2)(MU-PHS)(2) AND NS/SYN-(ETA(5)-MECOC5H4)(2)MO-2(CO)(2)(MU-PHS)(2)/

Reaction of Mo=Mo triply bonded complexes [eta(5)-RC5H4Mo(CO)(2)](2) w ith the Fe/S butterfly compound (mu-PhS)(2)Fe-2(CO)(6) in refluxing xy lene gives two corresponding Mo=Mo doubly bonded complexes (eta(5)-RC5 H4)(2)Mo-2(CO)(2)(mu-PhS)(2). Each of the complexes consists of two is omers, namely trans/anti and trans/syn, in terms of the relative arran gement of the RC5H4 and CO ligands and the mutual orientation of the p henyl groups on the bridging sulfur atoms. The two isomers with R = Me CO are convertible to each other in xylene at reflux and have been cry stallographically determined by X-ray diffraction. Further reactions o f the R = MeCO complex with NaBH4 and MeMgI afford two corresponding f unctional hydroxyl derivatives [eta(5)-MeCH(OH)C5H4](2)Mo-2(CO)(2)(mu- PhS)(2) and [eta(5)-Me2C(OH)C5H4](2)Mo-2(CO)(2)(mu-PhS)(2).